Steel 4147
AISI/SAE 4147 · UNS G41470
4147 is a higher-carbon chromium-molybdenum alloy steel (UNS G41470) that sits between 4145 and 4150 in the SAE-AISI 41xx family, with a 4147H hardenability-controlled version.
Reference datasheet — 4147 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT2832 condition
4147 tempers and conditions
4147 is supplied in 13 conditions, soft to hard. QT2832 is the default FabDigit quotes; the values on this page are for it.
Compare all 13 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose for maximum cold formability/heading and easiest machining of this high-carbon Cr-Mo grade. | 390 | 640 | 25 | 10 HRC | 8 % IACS |
Solution annealed | Softest condition for machining, deep drilling and forging stock before final heat treatment. | 415 | 690 | 22 | 197 HB | — |
Hot rolled | Lowest-cost mill condition for parts that will be re-heat-treated after machining or forging. | 570 | 900 | 15 | 26 HRC | 7.8 % IACS |
Cold drawn | Straight, close-tolerance bright bar for shafts machined to size without further heat treatment. | 670 | 790 | 14 | 21 HRC | 7.8 % IACS |
Normalized | Refines forging structure and gives uniform machinable hardness before quench and temper. | 690 | 1,075 | 13 | 33 HRC | 7.8 % IACS |
QT2832Default Q&T 28–32 HRC | Standard stocked quenched-and-tempered bar/forging: best balance of strength, toughness and machinability. | 860 | 965 | 17 | 30 HRC | — |
Induction hardened | Pick for journals, pins and gear teeth needing a 55–60 HRC wear case over a tough 28–32 HRC core. | 860 | 965 | 15 | 57 HRC | 7.5 % IACS |
H-band hardenability grade | Order when Jominy hardenability band (not just chemistry) must be guaranteed for heavy sections. | 860 | 965 | 17 | 30 HRC | 7.8 % IACS |
Q&T 32–36 HRC | Higher-strength shafting, tool joints and drill-string components still readily machinable. | 980 | 1,080 | 15 | 34 HRC | — |
Q&T 36–40 HRC | For heavily loaded gears, spindles and dies where wear resistance outranks toughness. | 1,140 | 1,240 | 13 | 38 HRC | — |
Q&T 40–44 HRC | High-strength forged tooling and wear parts; machining requires carbide, grinding often preferred. | 1,280 | 1,380 | 12 | 42 HRC | — |
Q&T 48–52 HRC | Wear-critical parts such as hammers, shear blades and mill liners; low toughness, ground finish. | 1,550 | 1,720 | 9 | 50 HRC | — |
Quenched and tempered at 205 °C | Maximum hardness/wear condition; only for compression-loaded or lightly stressed wear surfaces. | 1,650 | 2,000 | 7 | 55 HRC | — |
What is 4147?
4147 is a higher-carbon chromium-molybdenum alloy steel (UNS G41470) that sits between 4145 and 4150 in the SAE-AISI 41xx family, with a 4147H hardenability-controlled version. It is chosen for heavy forged and through-hardened components and is stocked annealed, spheroidized, hot-rolled, normalized, cold-drawn, induction-hardened and in quench-and-temper bands from 28–32 HRC to 48–52 HRC. The default condition gives 860 MPa yield, 965 MPa tensile, 17 % elongation and 285 HB (30 HRC), with service to about 425 °C and machinability rated 45. Weldability is poor (CE ≈ 0.85); use 4140 or 4137 when welding is unavoidable. 4147 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F). 4147 has a yield strength of 860 MPa (125 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 89% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi).
What is 4147 used for?
- forged shafts
- springs
- tool components
Advantages
- High strength — 860 MPa (125 ksi), better than 89% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
4147 properties
Typical room-temperature values for 4147-QT2832; bars are the position among steel grades.
Physical3
4147 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F).
Mechanical16
4147 has a yield strength of 860 MPa (125 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 89% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4147 is rated for continuous service to 425°C (797 °F). It conducts heat at 42.6 W/m·K (24.6 BTU/hr·ft·°F), worse than 51% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
4147 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 4147 takes about 29 MJ of energy and emits 2.2 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability8
4147's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (30/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 4147 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 4147
Is 4147 easy to machine?
Machine in annealed (~197 HB) or ≤32 HRC Q&T condition with rigid setups and coated carbide; above 40 HRC use ceramic/CBN or grind.
Can 4147 be welded?
Poor weldability (CE ≈ 0.85): preheat 200–320 °C, low-hydrogen consumables, interpass control and immediate post-weld temper below the tempering temperature.
Can 4147 be formed, bent or molded?
Hot forge 1150–1230 °C, finish above 900 °C and slow-cool/anneal; cold forming limited to spheroidize-annealed stock with generous radii.
4147 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CSAE J404 | 0.45 – 0.5 | 0.47 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.8 – 1.1 | 0.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| P | ≤ 0.04 | |
| Smax; resulfurized 4147 variants run higher | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 4147?
Not anodizable — use oil, manganese phosphate, black oxide, zinc or hard chrome; bake after plating to avoid hydrogen embrittlement above 40 HRC.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 4147 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- G41470
How much does 4147 cost?
4147 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
4147 — frequently asked
What is 4147 used for?
4147 is typically used for forged shafts, springs and tool components. In short: higher-carbon 4140 upgrade; deep-hardening forging grade; poor weldability.
What is the yield strength of 4147?
4147 has a typical yield strength of 860 MPa (125 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 89% of steel grades. Strength varies by condition: see the 13 listed tempers.
Is 4147 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in annealed (~197 HB) or ≤32 HRC Q&T condition with rigid setups and coated carbide; above 40 HRC use ceramic/CBN or grind.
Can 4147 be welded?
Not readily — weldability is rated poor (30/100). Poor weldability (CE ≈ 0.85): preheat 200–320 °C, low-hydrogen consumables, interpass control and immediate post-weld temper below the tempering temperature.
What surface finishes work on 4147?
Not anodizable — use oil, manganese phosphate, black oxide, zinc or hard chrome; bake after plating to avoid hydrogen embrittlement above 40 HRC.
Can 4147 be formed, bent or molded?
Hot forge 1150–1230 °C, finish above 900 °C and slow-cool/anneal; cold forming limited to spheroidize-annealed stock with generous radii.
What is the maximum service temperature of 4147?
4147 is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4147-QT2832 and 4147-QT205?
QT2832 is the default condition — standard stocked quenched-and-tempered bar/forging: best balance of strength, toughness and machinability. QT205: maximum hardness/wear condition; only for compression-loaded or lightly stressed wear surfaces. Yield strength is 860 MPa in QT2832 versus 1,650 MPa in QT205.
How much does 4147 cost?
4147 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Alloy H Steels — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- GB/T 3077 (45CrMo ) — SAC (2015)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.